Glenn will mark 50 years in the meat business this summer. He says he learns something new every day, and to impart his ever-expanding wisdom, he and consulting chef Chris Brill teach classes at Great News! Cooking School in San Diego.

On a recent Monday night they held court before a sold-out crowd to explain the cooking rules for "Center of the Table" meats, those big, impressive roasts that people like to serve for holidays such as Easter and Passover.

Their mantra? Use. A. Meat. Thermometer.

"For around $10, you are buying an insurance policy," said Glenn. "If you save one roast, the thermometer has paid for itself."

Indeed. At Iowa Meat Farms and Siesel's, a certified Angus beef USDA prime standing rib roast is a real investment, going for $13.99 a pound. A boneless, no-water-added ham is $5.99 a pound.

"I tell people, 'You see chefs walking around, and on their sleeve is a little pocket, and in that pocket is a thermometer,' " said Glenn. "If the chef needs a thermometer, you need one, too."

Both Iowa Meat Farms and Siesel's Old Fashioned Meat offer lots of printed support materials, covering everything from roasting to grilling to rib cookery. When writing guidelines, Glenn searched the Web — including sites for the National Cattlmen's Beef Association and the American Lamb Board — and went through about "5 billion cookbooks."

"I didn't agree with any of them," Glenn said. "It's amazing the different temperatures you get, especially from the older cookbooks."

His current research prompted him to tweak a guide he wrote two years ago in which he advocated 130 degrees as the ideal temperature for rare meat. Now he recommends 120 to 125 degrees for rare.

"If you are talking about pull-out-of-oven time or the temperature at serving time, right away you are off base," said Glenn. "And the tricky part is that those pull-out-of-the-oven temperatures depend on the diameter of what you are cooking, not the weight."

Glenn used his own Christmas Eve prime rib by way of illustration. He pulled the mammoth roast out when the meat thermometer registered 125 degrees, but as the meat rested, the thermometer soared out of the rare zone. The bigger the piece of meat, the more heat it retains.

Roasts that are smaller in diameter, such as a beef tenderloin or leg of lamb, can be pulled from the oven closer to the desired temperature (such as 125 for rare) because they will cool faster and not have as much carry-over cooking.

A leg of lamb is almost a no-brainer, Glenn said. Unlike beef, lamb does not have a huge difference in size from animal to animal. Two hours at 350 degrees F is standard cooking time, but you have to know what your oven is going to do, he said.

Glenn sells Berkshire pork (sometimes called Kurobuta in restaurants) from Minnesota. He scoffs at supermarket pork and how easy it is to overcook.

"Modern pork is terrible," he said matter-of-factly. "It goes back 30 years, when the industry decided that we wanted lean pork, and they set about to do that. They kept breeding leaner and leaner pork and took all the flavor out. It is most critical not to overcook pork. Do not go over 150 degrees."

But then, Glenn's take on all supermarket meat is less than charitable.

"Buying meat in the grocery store is like going to the dentist to have your eyes checked. It doesn't work."

Baking a ham is another ballgame entirely, because hams are sold already fully cooked. They just need a warm-up. And therein lies the problem.

Hams sold in supermarkets and big-box stores such as Costco have water added, Glenn said. Consumers tend to keep ham in the oven so long that the water cooks away, leaving a very salty product.

To avoid this, Glenn suggests customers buy a no-water-added ham or treat the meat more judiciously.

"Remember, you are heating, not cooking," he said. "Heat the ham at a lower temperature (300 degrees) for a longer period, and bring the internal temperature no higher than 140 degrees."

But ultimately, cooking a large cut of meat simply requires practice. "There is not an accurate home oven anywhere," Glenn said. "You have to learn what your oven will do, and that takes practice."

Keep it simple

In classes, Brill is in charge of teaching students how to protect their carnivore investment by not glopping it up with a lot of unnecessary adornments.

"Generally, the larger the roast, the less you want to season it," said Brill. "First, the flavor is not going to penetrate inside a large roast, and second, the longer you have to cook a big piece of meat, any rub or garlic or spice will have a chance to burn and give off a bitter taste."

Brill also said some roasts, such as prime rib, have a fat cap that is best left on during cooking to protect the meat and keep it moist. But seasonings don't penetrate the fatty layer, which is discarded after cooking.

You can infuse flavor in a leg of lamb by piercing the meat at intervals with a sharp knife and inserting slivers of garlic into the cuts. Just take care not to make the cuts too deep or too numerous, or you run the risk of losing flavorful juices.

Smaller roasts that don't take forever to cook — a rack of lamb or a pork roast, for example — can do nicely with a rub of spices, Brill said. He favors dried thyme, garlic powder or herbes de Provence.

But ultimately, you want to taste the quality of the meat you paid such a pretty penny for. For that, look no further than the dynamic duo of the kitchen, salt and pepper.

"I don't want to taste a sauce. I want to taste my rib-eye steak," said Glenn. "I'm very much a salt and pepper kind of guy."

TIPS FOR SUCCESSFUL ROASTING

To ensure the best results, do what the pros do and use a good meat thermometer. Take your reading at the center of the roast, not touching bone, and use this guide:

A good meat thermometer doesn't have to be pricey. Get one that can be adjusted with a little nut at the base of the dial. Test it at least once a year in ice water. If it registers 32 degrees, you know it's accurate.

Dry-roasting in a preheated, 350-degree oven is the simplest method.

If you want a range of doneness, start the roast in a 400-degree oven and turn the heat down to 350 degrees after 20 minutes. The ends of the roast will be more done than the center.

Doneness (for lamb and beef):

Rare: 120 to 125 degrees

Medium rare: 130 degrees

Medium: 135 degrees

Pull the roast out at the desired temperature and let it rest so the meat can reabsorb the juices. The larger the diameter of the meat, the longer it should rest, but figure at least 10 to 15 minutes.

Preheat oven to 400 F. Rub roast with a little olive oil and season to taste with salt and pepper. Place in center of oven and roast to an internal temperature of 125 to 130 F, about 20 to 25 minutes. Remove from oven and let rest 10 minutes before carving.

To make compote: In a small saucepan over medium-low heat, melt butter and cook red onion gently without browning until onion is soft and translucent. Add ginger, balsamic vinegar, brown sugar, dried cherries and enough port wine to cover cherries, and simmer until cherries are soft and liquid has thickened. Serve warm or at room temperature.

To make couscous: Heat olive oil in a small pot over medium heat. Add onion and saute until translucent. Add couscous and stir briefly, until couscous is lightly toasted.

Add boiling broth. Stir well and bring to a simmer. Cover and simmer until broth has been absorbed and couscous is tender, about 8 to 10 minutes. Remove from heat and let cool slightly. Gently fold in roasted peppers, cheese and parsley. Season to taste with salt and pepper.

To present at table, place roast on a large serving platter. Spoon couscous into center of crown. Spoon compote onto platter around roast.

Note: Israeli couscous is sold in specialty food stores such as Trader Joe's.

To prepare lamb: Preheat oven to 350 F. Make several small slits inside and outside of lamb leg with the tip of a paring knife and insert slivered garlic. Season inside and outside of leg generously with herbs, salt and pepper. Tie leg with butcher's twine.

Place lamb leg in oven and roast to internal temperature of 125 degrees (1 to 1 1/2 hours). Remove lamb from oven and let rest for 10 to 15 minutes before slicing.

For pesto: Combine all pesto ingredients in a bowl and mix well. Serve at room temperature with lamb.